BOSTON, June 13, 2012— Rhythm announced today that it has raised $25 million in a Series B financing round. All existing investors participated in the round—MPM Capital (MPM), New Enterprise Associates (NEA), and Third Rock Ventures (TRV)—as well as new investor, Ipsen (Euronext: IPN; ADR: IPSEY). The Series B financing brings the total capital raised by Rhythm to $65 million.

Rhythm will use the proceeds to continue advancing its small-peptide therapeutics for metabolic diseases through Phase 2 clinical trials. RM-131 is a ghrelin agonist currently in a Phase 2 clinical trial for the treatment of diabetic gastroparesis. RM-493, an agonist of the melanocortin 4 receptor (MC4R), is currently in Phase 1 clinical trials for the treatment of obesity and diabetes.

“We have made great progress since we started both development programs in 2010, and this could only have been achieved with a strong and dedicated investor syndicate,” said Bart Henderson, Founder and President of Rhythm. “These programs have great potential for addressing major unmet needs in diabetes, obesity, and gastrointestinal functional disorders, and this financing supports a broad and thorough Phase 2 development program for both drugs.”

“Ipsen is impressed with the early results for the ghrelin and MC4 programs as well as Rhythm’s track record in executing a precision development program,” said Marc de Garidel, Chairman and CEO of Ipsen. “Rhythm’s management team has our full support, and we are excited to become an investor in this Series B financing.”

“We see the potential for transforming the treatment of diabetes and other metabolic diseases with molecules that activate the ghrelin and MC4R pathways with high potency and specificity,” said Lou Tartaglia, PhD, a Partner at Third Rock Ventures. “We are pleased to invest in Rhythm and to be working with a great management team as it moves this exciting portfolio of peptides forward.”

In connection with the financing, Vaughn Kailian, Managing Director of MPM Capital, will join Rhythm’s board. He joins board members Keith Gottesdiener, MD, CEO of Rhythm; Ed Mathers, a Partner at NEA; Lou Tartaglia, PhD, a Partner at Third Rock Ventures; and Christian de la Tour, Chairman of Ipsen UK Companies.

About Rhythm (www.rhythmtx.com)

Rhythm is a biotechnology company developing peptide therapeutics that address unmet needs in metabolic diseases. Rhythm is developing the ghrelin peptide agonist, RM-131, for the treatment of diabetic gastroparesis and other GI functional disorders, and the MC4R peptide agonist, RM-493, for obesity and diabetes. Rhythm investors include MPM Capital, New Enterprise Associates, Third Rock Ventures, and Ipsen. The company is based in Boston, Massachusetts.